Features of the structural and optical properties of InGaN layers obtained by the MBE PA method with a pulsed supply of metal flows

This paper presents the results of studying the properties of InGaN layers with a high InN content (80–90%) obtained by molecular beam epitaxy with plasma activation of nitrogen on sapphire substrates with AlN/GaN buffer layers. The InGaN layers were formed using the metal modulated epitaxy (MME) method, as well as in nitrogen and metal rich conditions. It was found that the use of the MME method leads to a decrease in the density of threading dislocations in the InGaN layers. Nevertheless, despite the higher dislocation density, the smallest threshold of stimulated emission of $\sim$ 20 kW/cm$^2$ at 77 K was obtained for the In$_{0.8}$Ga$_{0.2}$N layer grown under nitrogen rich conditions, which is associated with the lowest background electron concentration in this sample (1.6$\cdot$10$^{19}$ cm$^{-3}$).